A virtualization based system provides a plurality of virtual nodes through virtualizing a physical node. That is, the virtualization based system improves the utilization of resources by dynamically allocating and releasing resources to/from a corresponding node according workload of a virtual node, which varies according to the abrupt change of business. In order to dynamically allocate and release resources, a physical node is divided into a plurality of virtual nodes through a virtual platform.
A high availability system improves the safety of a service that is directly provided to target users through an Internet or a cellular network according to a type of company operation or a type of business. In general, contents for a corresponding service are clustered through N nodes that are shared through a sharing storage.
Such a high availability clustering system generally provides an active/backup node structure by connecting two servers. The backup node monitors the active node while the active node occupies resources and provides services based on the occupied resources. Here, if failures are generated in the active node, the backup nodes takes over the resources of the active node and continuously provides a corresponding service based on the resources. As described above, the seamless service can be provided to a target user through such an active/backup node structure.
Hereinafter, a 1+1 high availability system according to the related art will be described with reference to FIG. 1.
As shown in FIG. 1, the 1+1 high availability system includes one active node 100-1 which is a server for providing a service and a backup node 100-2 for monitoring the active node 100-1.
The active node 100-1 and the backup node 100-2 include high availability managers 110-1 and 110-2, respectively. The high availability manager 110-1 of the active node 100-1 transmits a state of the active node 100-1 as a form of a HEARTBEAT message to the backup node 100-2 at a regular interval in order to inform the high availability manager 110-2 that the active node 100-1 successfully provides a service.
If the backup node 100-2 is informed that failures are generated in the active node 100-1, the backup node 100-2 determines that failures are generated in the active node 100-1 and performs a failover process for taking over the resources of a service that the active node 100-1 provides.
However, the 1+1 high availability system has availability limitation because the 1+1 high availability system cannot continuously provide a corresponding service if failures are generated in a backup node. Also, the 1+1 high availability clustering system constituted of two servers cannot form a multiple backup system which is required according to the importance of business. Therefore, it is difficult to apply the 1+1 high availability clustering system to a communication equipment server that forms a multi-level high availability system.
Hereinafter, a 1+m high availability system according to the related art will be described with reference to FIG. 2.
As shown in FIG. 2, the 1+m high availability system includes one active node 200-1 and (N−1) backup node 200-2 to 200-N. The active node 200-1 and the backup nodes 200-2 to 200-N include high availability managers 210-1 to 210-N for generating and transmitting a HEARTBEAT message that informs the state of each system.
For example, if a failure is generated in the active node 200-1, all of the backup nodes 200-2 to 200-N vote to select a backup node that will perform a failover process for taking over the resources of a corresponding service by transiting a state of the selected backup node as an active node. The selected backup node takes over the resources of a service that was provided by the active node 200-1.
However, the 1+m high availability system constantly generates a HEARTBEAT message to enable all of nodes to share cluster membership information although the 1+m high availability system provide better high availability than the 1+1 high availability system because the 1+m high availability system include (N−1) backup nodes. The constant generation of the HEARTBEAT messages causes the increase of cluster nodes, thereby generating the large amount of overhead for processing the HEARTBEAT message at a network and at each of nodes. Also, the utilization of resources deteriorates in the backup nodes except the active node, and the management cost increases due to the increment of nodes that do not provide actual services.